Obesity caused by fast-food diets, a growing scourge of American society, is now even affecting wild bears, researchers in the United States have found.Black bears living near American towns and cities are changing their feeding habits, devoting more and more time to raiding rubbish bins and tips, and in conseqeuence growing overweight from the left-overs of fast-food meals, said the Wildlife Conservation Society (WCS) in New York.High-calorie, high-fat diets have led to record levels of obesity among people and even domestic pets in the US. Now a study organised in Nevada has found that black bears living near urban areas...